Mootools

[hawky]

$(function() {
   	   var backgroundheight = 2000;
   	   offset = Math.round(Math.floor(Math.random()* 2001));
 
	function scrollbackground() {
   		offset = (offset < 1) ? offset + (backgroundheight - 1) : offset - 1;

		$('#layer').setStyles('background-position', '50% ' + offset + 'px');

   		setTimeout(function() {
			scrollbackground();
			}, 50
		);
   	}
	scrollbackground();
});

Wat is mijn fout in deze ($('#layer').setStyles('background-position', '50% ' + offset + 'px') regel?

 

[hawky]

document.getElementsByTagName('body')[0].style.backgroundPosition = ''+offset+'px top';